Vast open plains. Immense spaces. Eerie silence. But any feeling of emptiness is an illusion. The plains of our planet support the greatest gatherings of wildlife on earth. At the heart of all that happens here is a single living thing, grass. This miraculous plant covers a quarter of all the lands of the earth. Grasslands exist wherever there is a little rain, but not enough to sustain the forest. Some are huge. The Central Asian Steppe alone extends 1/3 of the way around our planet. It's summer and eagles effortlessly cruise the thermals scanning the ground beneath for signs of prey. In the distant reaches of Outer Mongolia one of the planet's great migrations is under way.


天地苍茫，万籁俱寂。在我们这个星球上，草原养育了最大的野生动物群体。这其中的原因却非常简单，是因为它有一种独有的东西，这就是青草。在地球的陆地上，有四分之一的面积被这种神奇的植物所覆盖。在有少量的降雨但又不足以维持森林生长的地方，就会形成草原。有些草原非常大，中亚大草原的跨度达地球周长的三分之一。 夏天，雕借着上升的暖气流，在空中悠闲地盘旋寻找猎物。在遥远的蒙古境内，一场迁徙正在进行，这是地球上最大规模的迁徙之一。